Innovative Heat Pump Powers Both Hot Tub and Ice Bath
A novel heat pump system developed at KTH Royal Institute of Technology is turning heads by simultaneously heating a hot tub and cooling an ice bath - using a single device.
The project, led by laboratory technician Albin Svensson and researcher Erik Björk from the Applied Thermodynamics and Refrigeration Engineering unit, demonstrates a clever rethinking of conventional heat pump technology.
Unlike traditional systems, which typically focus on either heating or cooling, this prototype harnesses both sides of the heat pump cycle. “We use the condenser to heat the hot tub and the evaporator to cool the cold bath,” Erik Björk explained. “That’s what makes it different from a regular heat pump.”
Designed primarily as a demonstration rig, the system aims to showcase how heat pumps work while highlighting new and efficient application possibilities. By leveraging both heating and cooling simultaneously, it illustrates how energy can be used more effectively in real-world scenarios.
The initiative is part of KTH’s Future Educations program, which funded the project. Through an ongoing collaboration with Swedish heat pump manufacturer NIBE , the finished system has been lent to the company for display at its headquarters in Markaryd.
The response has exceeded expectations. “The reactions when we tested the finished product were unexpectedly positive,” said Björk. “We had barely completed it before NIBE wanted to showcase it.”
The project underscores both the educational and technological potential of innovative energy systems—offering a glimpse into how future heating and cooling solutions might operate more sustainably.